Khan Academy

Khan Academy

Publisher

Following Khan Academy See all 16329 followers

Search: SEARCH

  • Mr. howard's avatar
    Visit http://www.HQteachers.org to connect you with thousands of parents searching for highly skilled and knowledgeable tutors. FREE registration
  • Mrs. Friedman's avatar
    Hi fellow Calculus teachers, It looks like I forgot to download this year's released PRACTICE AP CALCULUS AB exam and now the College board Teacher Login website it down for maintenance through March 3. I am supposed to give a mock AP this Sunday! Does anyone have the file downloaded and willing to share with me? Thanks!

    Nicole Friedman
    Yavneh Academy of Dallas
  • Mrs. Friedman's avatar
    Calculus teachers, I just gave my students a practice Free response from an old AP. I was checking the answer by computing the numerical integral in my calculator. I get two DIFFERENT answers depending on the method used! Explanation would be greatly appreciated!

    Here's the problem:

    The definite integral of |sin (x^2)| from 0 to 3.
    When I graph the function and use 2nd, trace, #7 I get that the answer is 1.7048233
    However, when I use fnInt on my home screen I get approximately 1.702!!!

    The A.P answer key says 1.702 but most of my students did it the other way and put 1.705.
    Help...
    Calculus teachers, I just gave my students a practice Free response from an old AP. I was checking the answer by computing the numerical integral in my calculator. I get two DIFFERENT answers depending on the method used! Explanation would be greatly appreciated!

    Here's the problem:

    The definite integral of |sin (x^2)| from 0 to 3.
    When I graph the function and use 2nd, trace, #7 I get that the answer is 1.7048233
    However, when I use fnInt on my home screen I get approximately 1.702!!!
    ...
    Show Full Post
    • Coach Haack - you can't use trace ... it's never exact. that's the problem. I teach AB and BC

      • Feb 6, 2015
    • Mr. Tabori - Trace uses an approximation from a visual graph - most likely this algorithm rounds inaccurately

      • Feb 6, 2015
    • Mrs. Friedman - Thank you!!!

      • Feb 6, 2015
  • Mrs. Liwanag's avatar
    Hello fellow teachers. Any new and creative way to teach mechanics to grade 8 and 9 students? :)
  • Mrs. McConnell's avatar
    Does anyone have any Khan Academy badges to share?
    • Mrs. McConnell - Awesome, thanks Barbra

      • Jan 26, 2015
    • Show 2 more replies...
      • Ms. Laura - I have a ton!

        • Jan 29, 2015
      • Mr. Withey - why dont yiu grt your students to make some? they would then "own" and have a greater value to them so might work harder to get them!

        • Feb 9, 2015
    • Mrs. Friedman - Can any Calculus teachers out there tell me if a Midpoint Riemann sum is ALWAYS more accurate than a Left or Right Riemann Sum? If not, what is a counter example? Thanks!

      • Jan 9, 2015
  • Mrs. Friedman's avatar
    Can any Calculus teachers out there tell me if a Midpoint Riemann sum is ALWAYS more accurate than a Left or Right Riemann Sum? If not, what is a counter example? Thanks!
    • Mr. Butler - If you had a trig function where the intervals were picked such that the function had a max or a min at the midpoint, and the L R points were more towards the average.
      For a standard power function, I would say that midpoint is probably going to be better - but for sinusoidals, I doubt that there is even better than random chance that one is better than the other. Even then for a power function, if you picked a function where a max /min was at the midpoint - I could see it being off.

      • Jan 12, 2015
    • Mrs. Friedman - Great example! Thanks so much! Very helpful :)

      • Jan 12, 2015
  • Mr. Hernández Garduza's avatar
    Muchas gracias a todos los docentes que con sus aportaciones me ayudaron a ser mejor sin que se enterarán; es motivante saber que hay mas personas preocupadas por formar a las generaciones venideras. Les deseo un año 2015 con salud y trabajo, también les deseo un año de amor con su pareja y si no la tienen ya vendrá. ¡¡¡Muchas felicidades!!!
  • Mr. Hernández Garduza's avatar
    Feliz Navidad a todos los maestros que participan en esta plataforma!!! he aprendido mucho de y con ustedes al leer sus posts, que la alegría este presente en sus corazones y que la compañia con sus amistades y/o seres queridos este llena de armonia. Nada de caras largas porque a palabras necias oidos sordos, Amen. ;-)
  • Mrs. Liwanag's avatar
    Any suggestions on which apps or other educational tools you use to teach electron configuration using tablets? Thanks in advance. :)
  • Mr. Hart's avatar
    It's time to start a revolution - not one based around tech or the next new strategy or research, but rather centered around relationships.
  • Delete Reply
  • Edit Reply
  • Delete Post
  • Edit Post
  • Link to this Post
  • Add Post to Library
  • Added to Library
  • Make Public

  • Hide
Most Recently Added
  • Most Recently Added
  • Featured

About

Khan Academy is on a mission to provide a free, world-class education for anyone, anywhere

Prekindergarten - Higher Education